package com.yyr.spring_boot.listener;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebListener;
import java.io.File;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

@WebListener
public class LogListener implements ServletContextListener {

    private final static Logger LOGGER = LoggerFactory.getLogger(LogListener.class);

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        LOGGER.debug("==== Init Log Listener ====");

        // 获取 /var/log 日志文件夹，判断是否存在，如果不存在直接返回
        File file = new File("/var/log");
        if (file == null) {
            return;
        }

        // 获取当前日期字符串
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-day");
        String currentDateString = dtf.format(LocalDateTime.now());

        // 获取/var/log 下日志文件列表，循环判断文件名字是否包含日期字符串，不包含则删除
        File[] files = file.listFiles();
        for (File tempFile : files) {
            String name = tempFile.getName();
            if (!name.contains(currentDateString)) {
                tempFile.delete();
            }
        }
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        LOGGER.debug("==== Destroyed Log Listener ====");
    }
}
